• 제목/요약/키워드: ISM: survey

검색결과 58건 처리시간 0.027초

HI 21 CM EMISSION LINE STUDY OF SOUTHERN GALACTIC SUPERNOVA REMNANTS

  • KOO BON-CHUL;KANG JI-HYUN;MCCLURE-GRIFFITHS N. M.
    • 천문학회지
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    • 제37권2호
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    • pp.61-77
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    • 2004
  • We have searched for HI 21 cm line emission from shocked atomic gas associated with southern supernova remnants (SNRs) using data from the Southern Galactic Plane Survey. Among the 97 sources studied, we have detected 10 SNRs with high-velocity HI emission confined to the SNR. The large velocity and the spatial confinement suggest that the emission is likely from the gas accelerated by the SN blast wave. We also detected 22 SNRs which show HI emission significantly brighter than the surrounding regions over a wide ($>10 km\;s^{-1}$) velocity interval. The association with these SNRs is less certain. We present the parameters and maps of the excess emission in these SNRs. We discuss in some detail the ten individual SNRs with associated high-velocity HI emission.

MODELLING OF THE RISKS FACED BY INDIAN CONSTRUCTION COMPANIES ASSESSING INTERNATIONAL OPPORTUNITIES

  • M.N. Devaya;N.K. Jha
    • 국제학술발표논문집
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    • The 2th International Conference on Construction Engineering and Project Management
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    • pp.140-149
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    • 2007
  • Indian construction companies have only 0.05% market share in the 3-4 trillion dollar global construction business and only two Indian construction companies figure in the ENR "Top 225 Global Contractors 2006" list. Hence, while enormous scope for growth exists, international construction experience is limited. This study explores the risks as perceived by Indian companies venturing abroad since risks in international construction differ from home market risks. Literature survey identified a number of risk factors that were evaluated by the experts, highlighting fourteen important risk factors. Interpretive Structural Modelling (ISM) was used to develop a hierarchical model showing the relationships between the different risk factors, thus helping to focus on the key risks for effective risk management. The study shows that poor project management is a key risk forming the hub of the system, while political instability has maximum influence. The results of the study can be used by managers to visualise the risks in perspective and prioritise the mitigation effort.

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현대 패션에 표현된 맥시멀리즘에 관한 연구 - 2000년대를 중심으로 - (A Study on Maximalism in the Modern Fashion - Focused on the 2000s -)

  • 박은경
    • 복식
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    • 제58권3호
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    • pp.1-18
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    • 2008
  • The tendency of exuberant multi-everything, enormous volumes and decoration has been showed in fashion since the 21st century. This tendency is very interesting in contrast to the tendency of restraint, simplicity and removing decoration which has been showed in the modern fashion throughout the 20th Century and especially minimalism fashion in the 1960s and the 1990s with the expectation of New Millenium. Maximalism is this kind of exuberant expression emerged since 2000. However, studies about maximalism in fashion have not been performed enough. Thus this study tried to analyze the aesthetic characteristics of maximalism in the modern fashion according to the previous studies of maximalism in design and architecture with social cultural background. The scope of this study was from 2000 to 2006, and this study was performed through literature survey with demonstrative analyzation of fashion collection photographs. The results are as follows; Maximalism has the meaning of 'maximum oriented-ism' and has aesthetic view of 'more/bigger is more beautiful.' The formativeness of maximalism in modern fashion was analyzed as fusion, enlargement, decoration, and fantasy. The internal meaning was analyzed as recovery of human being through pursuing of sensibility, fun and newness.

NEAR-IR POLARIMETRY AROUND 30 DORADUS: I. SEPARATION OF THE GALACTIC SOURCES

  • Kim, Jae-Yeong;Pak, Soo-Jong;Choi, Min-Ho;Kang, Won-Seok;Kandori, Ryo;Tamura, Motohide;Nagata, Tetsuya;Kwon, Jung-Mi;Kato, Daisuke;Jaffe, Daniel T.
    • 천문학회지
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    • 제44권4호
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    • pp.135-142
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    • 2011
  • A $200'{\times}200'$ region around 30 Doradus in the Large Magellanic Cloud (LMC) is observed and analyzed in the near-infrared. We obtain polarimetry data in the J, H, and Ks bands using the SIRIUS polarimeter SIRPOL at the Infrared Survey Facility 1.4 m telescope. We measure the Stokes parameters of 2562 point-like sources to derive the degree of polarization and the polarization position angles. We discuss the statistics of the groups classified by color-magnitude diagram and proper motions of the sources, in order to separate the Galactic foreground sources from those present in the LMC. We notice that groups classified by the proper motion data show a tendency towards different polarimetric properties.

Are There Any Old Globular Clusters in the Starburst Galaxy M82?

  • 임성순;황나래;이명균
    • 천문학회보
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    • 제36권1호
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    • pp.63.1-63.1
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    • 2011
  • M82 is a famous starburst galaxy which is dominated by young stellar populations and ISM. Some previous studies indicated the existence of intermediate-age and old stellar population in this galaxy, but little is known about them. We present a study of old globular clusters in M82 using the Hubble Space Telescope archive data. From the cluster survey of M82 we found 650 star clusters. We divided them into disk and halo star clusters according to their position. The color-color diagrams show that all 19 halo star clusters are old globular clusters. The disk sample may include both reddened young clusters and geniune old globular clusters. We estimated their ages using spectral energy distribution fit method with six filter data covering from ultraviolet (F330W) to infrared (F160W), and found that 30 of them are older than 3 Gyr. These are considered to be disk globular clusters. Twelve of the halo globular clusters are found to be partially resolved into their member stars. The (B-V) color range of the halo globular clusters is consistent with that of the Milky Way globular clusters, but most of M82 globular clusters are bluer than (B-V)=0.7. The existence of these old globular clusters suggests that the starburst galaxy M82 has an old stellar halo that may be as old as the Milky Way halo.

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LIFECYCLE OF THE INTERSTELLAR DUST GRAINS IN OUR GALAXY VIEWED WITH AKARI/MIR ALL-SKY SURVEY

  • Ishihara, D.;Kaneda, H.;Mouri, A.;Kondo, T.;Suzuki, S.;Oyabu, S.;Onaka, T.;Ita, Y.;Matsuura, M.;Matsunaga, N.
    • 천문학논총
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    • 제27권4호
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    • pp.117-122
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    • 2012
  • The interstellar dust grains are formed and supplied to interstellar space from asymptotic giant branch (AGB) stars or supernova remnants, and become constituents of the star- and planet-formation processes that lead to the next generation of stars. Both a qualitative, and a compositional study of this cycle are essential to understanding the origin of the pre-solar grains, the missing sources of the interstellar material, and the chemical evolution of our Galaxy. The AKARI/MIR all-sky survey was performed with two mid-infrared photometric bands centered at 9 and $18{\mu}m$. These data have advantages in detecting carbonaceous and silicate circumstellar dust of AGB stars, and the interstellar polycyclic aromatic hydrocarbons separately from large grains of amorphous silicate. By using the AKARI/MIR All-Sky point source catalogue, we surveyed C-rich and O-rich AGB stars in our Galaxy, which are the dominant suppliers of carbonaceous and silicate grains, respectively. The C-rich stars are uniformly distributed across the Galactic disk, whereas O-rich stars are concentrated toward the Galactic center, following the metallicity gradient of the interstellar medium, and are presumably affected by the environment of their birth place. We will compare the distributions of the dust suppliers with the distributions of the interstellar grains themselves by using the AKARI/MIR All-Sky diffuse maps. To enable discussions on the faint diffuse interstellar radiation, we are developing an accurate AKARI/MIR All-Sky diffuse map by correcting artifacts such as the ionising radiation effects, scattered light from the moon, and stray light from bright sources.

조건부가치측정법(CVM)을 이용한 정보보호 관리체계(ISMS) 인증의 경제적 가치 추정 연구 (Estimating The Economic Value of Information Security Management System (ISMS) Certification by CVM)

  • 장상수
    • 한국산학기술학회논문지
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    • 제15권9호
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    • pp.5783-5789
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    • 2014
  • 국내 많은 기업들이 2002년부터 ISMS를 구축하고 인증을 받아 운영하고 있지만 인증 취득 필요성이나 경제적 효과성 등의 평가는 구체적으로 시행되고 있지 않다. 따라서 10년 이상 시행되고 있는 ISMS 인증 제도에 대해 어떠한 성과가 있고 기업 경영에 어떤 경제적 효과가 있는지 검증할 필요가 있다. 본 연구에서는 인증 취득에 따른 효과분석 모델 개발과 인증의 경제적 가치를 측정하여 제시하고자 하였다. 이를 위하여, ISMS 인증유지 조직을 대상으로 개방형 질문법을 이용 설문조사와 조건부가치측정법(CVM)을 통해 분석한 결과 인증 기업당 매년 1억 7,130만원 상당의 경제적 가치가 있는 것으로 추정되었다. 본 연구 에서는 조건부가치측정법을 활용한 ISMS 인증 서비스의 경제적 가치를 추정하는 방법을 제시하였으며, 측정 지표와 방법을 통해 기업 스스로 인증의 경제적 가치를 추정해봄으로써 ISMS 운영의 실효성을 확보하고 최고경영진의 정보보호 투자 등 의사결정에 많은 도움이 될 것으로 보인다.

항해사의 피로가 해양사고에 미치는 영향 평가에 관한 연구 (A Study on the Effects of Marine Accidents by Navigation Officers' Fatigue)

  • 조준영;금종수;장운재
    • 해양환경안전학회지
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    • 제16권2호
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    • pp.201-207
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    • 2010
  • 최근 국내에서는 연간 약 600여건의 각종 해양사고가 발생하고 있다. 해양사고의 발생에 관한 국 내외 많은 연구와 분석에 의하면 해양사고의 약 70~80%가 인적요인에 의해 발생하고 있다. 여러 인적요인 중에서도 항해사의 피로는 매우 중요한 요인이다. 항해사의 피로가 해양사고에 중요한 역할을 한다고 인식되고 있음에도 불구하고 항해사의 피로도를 정량적으로 파악할 수 있는 연구는 거의 미미하다. 따라서 본 연구에서는 해양사고 종류별로 인적요인에 의한 발생률을 분석하고, 문헌과 5점 척도를 이용한 설문조사를 통하여 항해사의 피로에 영향을 미치는 중요한 5가지 요인을 추출하였다. 그리고 ISM법을 이용하여 피로요인에 의한 해양사고 발생 위험성의 평가요소를 계층구조화하였다. 마지막으로 AHP법을 이용하여 추출된 각 피로요인의 중요도를 구하고 항해사의 피로에 의해 발생할 가능성이 높은 해양사고의 순위를 결정하였다. 그 결과 수면시간 0.386, 스트레스 0.302, 건강상태 0.139, 휴식시간 0.099, 음주 약물 0.074순으로 높은 것으로 나타났다. 또한, 인명사상사고 0.328, 충돌사고 0.308, 좌초사고 0.195, 침몰사고 0.094, 화재사고 0.075로 나타났다. 따라서 중요도가 높은 요소들을 중심으로 제어방안을 마련해야 할 필요가 있다.

FOLLOW-UP OBSERVATIONS TOWARD PLANCK COLD CLUMPS WITH GROUND-BASED RADIO TELESCOPES

  • LIU, TIE;WU, YUEFANG;MARDONES, DIEGO;KIM, KEE-TAE;MENTEN, KARL M.;TATEMATSU, KEN;CUNNINGHAM, MARIA;JUVELA, MIKA;ZHANG, QIZHOU;GOLDSMITH, PAUL F;LIU, SHENG-YUAN;ZHANG, HUA-WEI;MENG, FANYI;LI, DI;LO, NADIA;GUAN, XIN;YUAN, JINGHUA;BELLOCHE, ARNAUD;HENKEL, CHRISTIAN;WYROWSKI, FRIEDRICH;GARAY, GUIDO;RISTORCELLI, ISABELLE;LEE, JEONG-EUN;WANG, KE;BRONFMAN, LEONARDO;TOTH, L. VIKTOR;SCHNEE, SCOTT;QIN, SHENGLI;AKHTER, SHAILA
    • 천문학논총
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    • 제30권2호
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    • pp.79-82
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    • 2015
  • The physical and chemical properties of prestellar cores, especially massive ones, are still far from being well understood due to the lack of a large sample. The low dust temperature (< 14 K) of Planck cold clumps makes them promising candidates for prestellar objects or for sources at the very initial stages of protostellar collapse. We have been conducting a series of observations toward Planck cold clumps (PCCs) with ground-based radio telescopes. In general, when compared with other star forming samples (e.g. infrared dark clouds), PCCs are more quiescent, suggesting that most of them may be in the earliest phase of star formation. However, some PCCs are associated with protostars and molecular outflows, indicating that not all PCCs are in a prestellar phase. We have identified hundreds of starless dense clumps from a mapping survey with the Purple Mountain Observatory (PMO) 13.7-m telescope. Follow-up observations suggest that these dense clumps are ideal targets to search for prestellar objects.

설마천 연구지역에서의 토양수분량을 활용한 유출 발생 특성분석 (An analysis of runoff characteristic by using soil moisture in Sulma basin)

  • 김기영;이용준;정성원;이연길
    • 한국수자원학회논문집
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    • 제52권9호
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    • pp.615-626
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    • 2019
  • 토양수분과 유출은 매우 밀접한 관계를 가지고 있으며, 특히 토양 내의 여러 요소들에 의해 토양의 수분보유능력과 배수의 특성이 결정된다. 본 연구에서는 2016년, 2017년 설마천 유역에서 총 40개의 사상을 분리하였다. 선정한 사상별로 constant-K 방법을 적용하여 직접유출과 기저유출을 분리하고 유출계수를 산정하였다. 산정된 유출계수는 선행토양함수와 지수함수 형태의 증가를 보였다. 또한 유출계수가 급증하기 시작하는 토양수분의 임계값을 선정하였으며, 이 값은 유출과 지하수면과의 큰 상관관계를 나타내었다. 선행토양함수뿐만 아니라 초기 토양수분, 토양 저류량, 강우량 등 여러 인자들도 유출 결과에 영향을 미치는 것으로 분석되었다. 또한 선행토양수분의 임계값에 따라 강우사상을 건조, 습윤 상태로 분리하여 시작 반응과 첨두 반응을 분석해 보았으며, 습윤 상태에서의 반응이 건조 상태에서 보다 빠르게 발생하였다. 건조 상태에 속하는 대부분의 사상에서는 토양수분이 정점에 도달한 후 지하수면과 유출량 순으로 정점에 도달하는 첨두 반응이 일어났으나 습윤 상태에서는 반대로 지하수면과 유출량이 토양수분보다 먼저 정점에 도달하였다. 본 연구의 결과는 유출에 기여하는 인자들 사이의 상호작용을 확인하고 토양의 다양한 조건과 유출 사이의 관계를 규명하는 데에 크게 기여할 것으로 판단된다.